1. Field of the Invention
The present invention relates to reflectors in satellite systems, and, more particularly, heating systems for reflectors in satellite systems.
2. Description of the Related Art
An antenna reflector, commonly called a dish, is generally a parabolic section having a round, elliptical or other configuration. A reflector functions to gather radio or microwave frequency energy transmitted from the feed horn or through the ambient environment from an external transmitter. The reflector can thus be used to receive and transmit signals to and from the satellite system. Typical applications include communicating data collected by a point of sale terminal in a store to the central data processing location. In this way, a large company can keep track of its sales and inventory requirements on an instantaneous basis. Maintaining a reliable satellite contact is absolutely essential. Reflectors are usually located outdoors, where snow and ice may collect on the receiving or concave side, degrading the performance of the reflector. If the link fails, store clerks have no way of executing any transactions with a customer. Thus, outages caused by snow and ice accumulation on the antenna reflector and feed are intolerable. In view of this, it is known to install heating apparatuses for deicing antennas in climates where snow and ice can present problems.
An antenna for the satellite terminal is often installed on the roof of the structure. Power line voltage is wired to the antenna for deicing purposes. Such power line voltage must be carried in a conduit on the outside of the building, or fed through an opening in the roof. Because of the distance between the power supply inside the building and the rooftop antenna, a relatively long piece of conduit is necessary. A problem is that the length of the conduit, coupled with the twisting, exposed path that the conduit must often take, subjects the conduit to being severed, shorted, or pulled loose from its connection due to its own weight. If the electrical connection between the conduit and the antenna is lost because of any of the above problems, the heater will not operate, snow and ice may collect on the reflector, and the performance of the reflector will be degraded.
It is also known to provide separate transmission lines to carry power to the antenna heater and to carry data between a terminal and the antenna. Such data and power lines are expensive, however, and each line is subject to breakage or shorting.
What is needed in the art is a heating system for a reflector which can, while minimizing the hardware needed to carry power and data to the reflector, sense a loss-of heater power and inform a user of the loss.